User blog comment:QueenShebaPunch/DmC: A Reboot or Alternate Universe?/@comment-1512913-20121101231232/@comment-976055-20121103034815

A spin-off is taking something from the existing content and making something else, like the Mega Man Zero and ZX series, Adventures of Tron Bonne, or Resident Evil: Outbreak and Dead Aim. Metal Gear AC!D or the new Metal Gear Rising (which is a what-if scenario, and has no bearing on the MGS canon, hence the dropping of "Solid" from the title). Metal Gear Solid: Ghost Babel, on the other hand, was an alternate universe, using existing elements.

DmC being an alternate universe does not make it a spin-off, it makes it an alternate universe. It goes back to the beginning to retell (reboot) Dante's origins (albeit with a different tone), just like Nolan's Dark Knight trilogy. While elements are different, there are many core elements that remain the same.

And "alternate universe" isn't some in-game plot contrivance, it's the developers tell you that it has no effect on the existing canon because they made their own.